Three dimensional structures serving as ink jet manifold and nozzles are formed in successive layers by photolithography and electrodeposition to surround one or more cavities. This is particularly suited for the manufacture of thick manifold and/or nozzle structures in MEMS-based ink jet print heads that create fluid channels or cavities through which ink or other fluids can flow.
Currently, electroplated structures fabricated for MEMS-type applications are typically made using a single layer of structural material that is micro machined. A few multiple layered structures have been fabricated using alternate deposition of structural and sacrificial layers. Examples of these include: U.S. Pat. No. 6,475,369 to Cohen, U.S. Patent Application Publication No. US2004/0004001A1 to Cohen et al., U.S. Patent Application Publication No. US2003/0234179A1 to Bang, U.S. Patent Application Publication No. US2003/0221968A1 to Cohen et al., U.S. Patent Application Publication No. US2004/004002A1 to Thompson et al., U.S. Patent Application Publication No. US2004/007468A1 to Cohen et al., U.S. Patent Application Publication No. US2004/0007469A1 to Zhang et al., U.S. Patent Application Publication No. US2004/0007470A1 to Smalley, U.S. Patent Application Publication No. US2004/0020782A1 to Cohen et al., U.S. Patent Application Publication No. US2004/0140862A1 to Brown et al., U.S. Patent Application Publication No. US2003/0127336A1 to Cohen et al., U.S. Patent Application Publication No. US2003/0183008A1 to Bang et al., and U.S. Patent Application Publication No. US2003/0222738A1 to Brown et al.
Because of the existence of MEMS structure on a die and the like, it is often necessary to provide a sealed or otherwise substantially enclosed structure of substantial thickness to enclose a device such as a MEMS device on a die. Forming such a deep hollow enclosed interior with defined channels and apertures sealed by a lid would be difficult to fabricate using a single layer of structural material. Thus, existing technology requires complicated fabrication processes.
Moreover, using standard surface micromachining techniques, sacrificial layers are typically in the range of 1-3 μm using SiO2 or other dielectric materials. Thickness also drops significantly when using evaporated or sputtered metals.